================================================================== BUG: KASAN: use-after-free in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:957 Read of size 1 at addr ffff88814e453fff by task klogd/2846 CPU: 0 UID: 0 PID: 2846 Comm: klogd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:957 __hid_input_report.constprop.0+0x314/0x460 drivers/hid/hid-core.c:2147 hid_irq_in+0x52e/0x6b0 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2011 handle_softirqs+0x1dd/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__orc_find+0x4f/0xf0 arch/x86/kernel/unwind_orc.c:101 Code: f0 49 39 fc 72 7b 48 b9 00 00 00 00 00 fc ff df 49 89 ff 48 89 fd eb 0c 48 8d 6b 04 49 89 df 49 39 ec 72 4e 4c 89 e2 48 29 ea <48> 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 RSP: 0018:ffffc9000194f4c0 EFLAGS: 00000212 RAX: ffffffff8b612d10 RBX: ffffffff8b069574 RCX: dffffc0000000000 RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffff8b069524 RBP: ffffffff8b06956c R08: ffffffff8b612d9a R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000011842 R12: ffffffff8b069570 R13: ffffffff8218429d R14: ffffffff8b069524 R15: ffffffff8b069568 orc_find arch/x86/kernel/unwind_orc.c:238 [inline] unwind_next_frame+0x2ec/0x2090 arch/x86/kernel/unwind_orc.c:510 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6e/0x70 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_node_noprof+0x26b/0x6b0 mm/slub.c:4950 __alloc_skb+0x140/0x710 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6734 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2998 unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2141 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x468/0x4b0 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f381a742407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffdbb999c80 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f381a5f2c80 RCX: 00007f381a742407 RDX: 000000000000006c RSI: 00007ffdbb999dc0 RDI: 0000000000000003 RBP: 00007ffdbb99a1f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffdbb99a208 R13: 00007ffdbb999dc0 R14: 0000000000000051 R15: 00007ffdbb999dc0 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14e453 flags: 0x200000000000000(node=0|zone=2) page_type: f0(buddy) raw: 0200000000000000 ffffea0005392fc8 ffffea000533a4c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000f0000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 19497, tgid 19497 (syz-executor), ts 1968564553898, free_ts 2030292112778 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0xf34/0x3a90 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x273/0x28a0 mm/page_alloc.c:5226 alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2490 alloc_pages_noprof+0x1a/0x160 mm/mempolicy.c:2581 vm_area_alloc_pages mm/vmalloc.c:3653 [inline] __vmalloc_area_node mm/vmalloc.c:3878 [inline] __vmalloc_node_range_noprof+0xf9a/0x1630 mm/vmalloc.c:4064 vmalloc_user_noprof+0x9e/0xe0 mm/vmalloc.c:4218 kcov_ioctl+0x4c/0x720 kernel/kcov.c:726 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 19503 tgid 19503 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x692/0xf10 mm/page_alloc.c:2943 vfree mm/vmalloc.c:3472 [inline] vfree+0x15f/0x8d0 mm/vmalloc.c:3436 kcov_put kernel/kcov.c:442 [inline] kcov_put kernel/kcov.c:438 [inline] kcov_close+0x34/0x60 kernel/kcov.c:543 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d2/0x2a60 kernel/exit.c:975 do_group_exit+0xd5/0x2a0 kernel/exit.c:1117 get_signal+0x1ec7/0x21e0 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x7e/0x430 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x682/0x7f0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88814e453e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88814e453f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88814e453f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88814e454000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88814e454080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: f0 49 39 fc lock cmp %rdi,%r12 4: 72 7b jb 0x81 6: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx d: fc ff df 10: 49 89 ff mov %rdi,%r15 13: 48 89 fd mov %rdi,%rbp 16: eb 0c jmp 0x24 18: 48 8d 6b 04 lea 0x4(%rbx),%rbp 1c: 49 89 df mov %rbx,%r15 1f: 49 39 ec cmp %rbp,%r12 22: 72 4e jb 0x72 24: 4c 89 e2 mov %r12,%rdx 27: 48 29 ea sub %rbp,%rdx * 2a: 48 89 d6 mov %rdx,%rsi <-- trapping instruction 2d: 48 c1 ea 3f shr $0x3f,%rdx 31: 48 c1 fe 02 sar $0x2,%rsi 35: 48 01 f2 add %rsi,%rdx 38: 48 d1 fa sar $1,%rdx 3b: 48 8d 5c 95 00 lea 0x0(%rbp,%rdx,4),%rbx